diff engine/core/util/base/singleton.h @ 0:4a0efb7baf70

* Datasets becomes the new trunk and retires after that :-)
author mvbarracuda@33b003aa-7bff-0310-803a-e67f0ece8222
date Sun, 29 Jun 2008 18:44:17 +0000
parents
children 90005975cdbb
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/core/util/base/singleton.h	Sun Jun 29 18:44:17 2008 +0000
@@ -0,0 +1,110 @@
+/***************************************************************************
+ *   Copyright (C) 2005-2008 by the FIFE team                              *
+ *   http://www.fifengine.de                                               *
+ *   This file is part of FIFE.                                            *
+ *                                                                         *
+ *   FIFE is free software; you can redistribute it and/or modify          *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program; if not, write to the                         *
+ *   Free Software Foundation, Inc.,                                       *
+ *   51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA              *
+ ***************************************************************************/
+
+#ifndef FIFE_SINGLETON_H
+#define FIFE_SINGLETON_H
+
+#define SINGLEFRIEND(classname) friend class FIFE::StaticSingleton<classname>; classname(); virtual ~classname();
+
+// Standard C++ library includes
+#include <cassert>
+
+// 3rd party library includes
+
+// FIFE includes
+// These includes are split up in two parts, separated by one empty line
+// First block: files included from the FIFE root src directory
+// Second block: files included from the same folder
+#include "fifeclass.h"
+
+namespace FIFE {
+
+	/** The "classic" Singleton.
+	 *
+	 * @see DynamicSingleton
+	 */
+	template <typename T> class StaticSingleton: public FifeClass {
+		public:
+
+			static T* instance() {
+				static T inst;
+				return &inst;
+			}
+
+		protected:
+
+			StaticSingleton(): FifeClass() {
+			}
+
+			virtual ~StaticSingleton() {
+			}
+
+		private:
+			StaticSingleton(const StaticSingleton<T>&): FifeClass() {}
+			StaticSingleton<T>& operator=(const StaticSingleton<T>&) {
+				return this;
+			}
+
+	};
+
+	/** Another Singleton.
+	 *
+	 * This implementations needs to be created and destroyed explicitly.
+	 * That way the order of construction and destruction is well defined, so we don't
+	 * get those nasty static initialization/destruction order problems.
+	 *
+	 * Engine will create all standard FIFE Singletons when created (just call Engine::instance())
+	 * and destroy them on exit.
+	 *
+	 * Maybe we'll change this one day to use one of those funny NiftyCounter implementations.
+	 *
+	 * @see StaticSingleton
+	 * @see Engine
+	 */
+	template <typename T> class DynamicSingleton: public FifeClass {
+		public:
+			static T* instance() {
+				assert(m_instance);
+				return m_instance;
+			}
+
+			DynamicSingleton(): FifeClass() {
+				assert(!m_instance);
+				m_instance = static_cast<T*>(this);
+			}
+
+			virtual ~DynamicSingleton() {
+				m_instance = 0;
+			}
+
+		private:
+			static T* m_instance;
+
+			DynamicSingleton(const DynamicSingleton<T>&): FifeClass() {};
+			DynamicSingleton<T&> operator=(const DynamicSingleton<T>&) {};
+
+	};
+
+	template <typename T> T* DynamicSingleton<T>::m_instance = 0;
+
+}//FIFE
+
+#endif